الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Neglected tropical diseases )NTD(, which affects more than 1 billion people with the lowest income in tropical and subtropical regions, represents a huge burden on public health and the economy. According to the World Health Organization (WHO), NTDs are a group of seventeen parasitic, bacterial, and viral infections including Chagas disease, leishmaniasis, lymphatic filariasis and schistosomiasis. Schistosomiasis (or Bilharzia) ranks second only to malaria in terms of human suffering in the tropics and subtropics. The introductory part of the the thesis highlights the prevalence of schistosomiasis worldwide and in Egypt. It also provides background information on the parasites involved in the different types of schistosomiasis, their life cycle, clinical manifestations of the infection, prevention and control methods. The introduction also provided an overview of the drugs which have been used in the control of schistosomiasis and placed emphasis on praziquantel as the current standard oral treatment of schistosomiasis and other parasitic diseases, highlighting its advantages and limitations which mainly poor bioavailability and development of resistance. Different approaches to overcome the limitations of praziquantel therapy such as the discovery and development of new drugs and the economic difficulties encountered in this respect, discovery of new therapeutic targets, drug repurposing, natural products and natural products compounds were surveyed. In addition, drug delivery technology and nanotechnology were discussed as an effective approach to improve the bioavailability and activity of existing drugs focusing on lipid-based systems investigated to date for the delivery of praziquantel. These include mainly liposomes, lipid nanoparticles, nanostructured lipid carriers and nanoemulsions. This up-to-date background information pointed to the need to develop new drug delivery systems allowing a greater enhancement of praziquantel effectiveness. This led to the thesis research hypothesis that was formulated based on the development of a new lipid-based praziquantel delivery system aiming at enhancing PZQ therapy. In theory, this could be achieved by a sufficiently high drug loading, adequate drug-vehicle-parasite interaction and structural integrity for possible gut uptake and access to the blood fluke. Lipid nanocapsules with favorable structural and biopharmaceutical characteristics were selected as a new nanocarrier with great promises for effective oral praziquantel therapy. Accordingly, the thesis objective was develop praziquantel lipid nanocapsules as a potentially effective new oral antischistosomal nanomedicine formulation.